Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Explain third degree atrioventricular block, Q. Explain Third Degree Atriov...

Q. Explain Third Degree Atrioventricular Block? In older patients with known or suspected CAD, third degree heart block at rest should be a relative contraindication to stress

Aves, What is aves?

What is aves?

Describe about the extra-ocular muscles, Describe about the extra-ocular mu...

Describe about the extra-ocular muscles The eye is comprised of extra-ocular and intra-ocular muscles. The extra-ocular muscles are comprised of 4 recti and 2 obliques. The rec

What is polymerase chain reaction, Which of the following is a false statem...

Which of the following is a false statement regarding Polymerase Chain Reaction (PCR)? A. PCR is a modified version of cellular replication that is used to amplify small amount

Explain pro-oxidants - lipid oxidation, Explain Pro-Oxidants Transitio...

Explain Pro-Oxidants Transition metals, particularly those possessing two or more valency states and a suitable oxidation - reduction potential between them (e.g., cobalt, cop

Inorganic nitrogen and sulphur metabolism, Inorganic Nitrogen and Sulphur M...

Inorganic Nitrogen and Sulphur Metabolism Productivity in agriculture, forestry and other ecosystems is basically limited by the availability of nitrogen nutrients like nitrat

Function of glutamate, Q. Function of Glutamate? Glutamate It is the...

Q. Function of Glutamate? Glutamate It is the principal excitatory transmitter in the brain and is found throughout the central nervous system. Receptors Glutamate rec

Explain about implant surgery, Explain about implant surgery Diagnosis ...

Explain about implant surgery Diagnosis and treatment planning for a patient who requires and is to receive dental implants. The actual process of dental implant placement begi

Explain class oligochaeta - earthworms in details, Explain Class Oligochaet...

Explain Class Oligochaeta - Earthworms in details? This group of annelids includes the earthworms. Oligochaetes live in the soil or in fresh water habitats, and a few inhabit m

Explain types known in metabolic pathways, How many regulatory enzyme types...

How many regulatory enzyme types known in metabolic pathways, explain in detail by giving examples.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd